Specialty fasteners such as blind fasteners are sometimes used to extend through an aperture defined in a sheet material that has a first side and a second side. Such fasteners typically extend through the aperture and are then actuated from the first side so as to expand and engage the second side of the sheet material such that the blind fastener may be secured within the aperture. These fasteners are also often used to affix two or more sheet materials together wherein one side of the materials is not readily accessible.
Some types of removable blind fasteners are also known for affixing two sheet metal layers having a first side and a second side wherein the fastener may be inserted through an aperture so as to affix the two sheet metal layers. For example, U.S. Pat. No. 2,857,950 to Tingley (the '950 patent) discloses a removable blind fastener with pivoted securing legs wherein the legs may be pivoted with respect to a body of the blind fastener so as to engage a second side of two layers of sheet metal. However, the '950 patent requires that the pivoted securing legs be secured to the second side by the use of additional bolts that must be inserted through the sheet metal layers to engage the pivoted securing legs with the second side. In addition, the '950 patent requires that the legs be pivoted into contact with the second side via wires having crimped ends to engage the pivoted leg through which it passes. Thus, the retractable blind fastener requires the actuation of the wires to engage the pivoted legs with the second side as well as the installation of at least two separate bolts to secure the pivoted legs to the second side.
Another type of blind fastener includes a “push-type” fastener that also may be removable and reusable. Such push-type fasteners may include a sleeve into which is slid a push bolt such that the blind fastener may be installed and removed by hand, without the use of any tools. For instance, U.S. Pat. No. 3,202,038 to Bass (the '038 patent) discloses a push-type blind fastener including a sleeve into which is slidably engaged a push bolt having a single annular locking and releasing groove defined therein. The push bolt may be pushed to a first position so as to engage a resilient locking and securing tab that are attached to the sleeve and resiliently biased inwardly with respect to the sleeve. In the first position, the push bolt may be positioned so as to urge the resilient locking and securing tabs laterally outward so as to engage an inaccessible surface of a workpiece so as to secure the sleeve with respect to an aperture defined in the workpiece. Further, the blind fastener of the '038 patent also provides that the push bolt may be pushed to a second position such that the annular locking and securing groove becomes aligned with the resilient locking and securing tabs so that they may return to their inwardly biased position with respect to the sleeve, thereby releasing their engagement with the inaccessible surface of the workpiece and allowing the sleeve (and blind fastener) to be removed completely from the aperture. While the blind fastener of the '038 patent is easily actuated without the use of tools, it also allows the blind fastener to be easily removed by the movement of the push bolt to the second position, and thus the blind fastener may be inadvertently removed when its removal is not desired. In addition, the resilient locking and securing tabs of the blind fastener of the '038 patent may experience fatigue such that the securing tabs may eventually lose their resilient inward bias such that the blind fastener may be rendered non-removable after repeated use. Also, the blind fastener of the '038 patent does not allow for adjustment of the distance between the resilient locking and securing tabs and a head of the blind fastener, and as such, the blind fastener may only securely and properly engage a workpiece having a single fixed thickness that is equivalent to the distance between the resilient locking and securing tabs and a head of the blind fastener.
Other types of blind fasteners may provide spring mechanisms for engaging the inaccessible side of one or more sheet materials through an aperture. While such spring mechanisms may provide a quick engagement with the inaccessible side, they also lack a mechanism for recoiling the spring mechanism. Thus, such spring mechanism blind fasteners may not be removable via the aperture once they are engaged with the inaccessible side. For instance, U.S. Pat. No. 4,722,649 (the '649 patent) to Ferguson describes a releasable fastening device for securing workpieces together, and includes an expandable device in the form of a stiff spring located within an annular recess in a shank of the fastening device. Furthermore, the '649 patent discloses a mechanism which releasably engages the spring and is capable of limiting the spring's extension to within the annular recess until such time as the fastener is inserted into an aperture defined in one or more workpieces. Once inserted, the mechanism may release the spring so that it may engage a bottom surface of a lower workpiece so as to secure the fastener within the aperture. The '649 patent's release mechanism, however, provides no mechanism for recoiling the spring, such that once the blind fastener is engaged with the bottom surface of the lower workpiece it may not be easily removed without damaging either the fastener or the workpiece. The releasable fastening device of the '649 patent also does not provide for the adjustment of the distance between the spring and a head of the fastening device such that the blind fastener may only securely engage sheet materials having a fixed thickness.
Other types of blind fasteners have been disclosed which may extend through an aperture defined in a material and be capable of engaging an inaccessible side of the material by actuating a mechanism on the accessible side of the blind fastener that acts to deform a portion of the blind fastener extending through the aperture to the inaccessible side of the material. For instance, U.S. Pat. No. 5,429,464 to Eshraghi (the '464 patent) discloses a blind fastener having a fastener body extending through an aperture defined by one or more workpieces. The body has a stem passing therethrough such that the stem may be pulled away from the workpieces from the first side in order to pull an anvil washer and an expander collar into the body so as to laterally expand and bulb the fastener body on the second side of the workpieces. Similarly, U.S. Pat. No. 6,224,309 to Yamamoto (the '309 patent) discloses a blind fastener having a hollow bolt for extending through an aperture defined by a workpiece. The blind fastener of the '309 patent also includes a threaded core bolt and a “pull up nut” engaged with the core bolt such that as the core bolt is turned within the hollow bolt, the pull up nut is “pulled up” into contact with the body portion of the hollow bolt so as to deform the body portion such that the deformed body portion engages the inaccessible side of the workpiece. In both the '464 and '309 patents, the blind fasteners may be actuated from the accessible first side of a workpiece so as to deform an inaccessible portion of the blind fastener. Both of these fasteners, however, require the deformation of a sleeve or body portion in order to engage an inaccessible side of the workpiece. Once deformed, however, these blind fasteners may not be easily removable without damaging one or more of the workpieces. In addition, once deformed, these blind fasteners may not be reusable.
Another type of blind fastener includes a spring-biased actuator pin and at least one pivotable toggle that also may be removable and reusable. For instance, U.S. Pat. No. 3,534,650 to Kubokawa (the '650 patent) discloses a fastener device having an adjustable length and including a sleeve into which is slidably engaged an actuator pin connected with four toggle wings and biased by a spring. In the device of the '650 patent, one or more apertured workpiece members are held together by tightening a lock nut against the extended toggle wings after having inserted the fastener through the workpiece members. The device of the '650 patent does not provide stop means for selectively maintaining the toggle wings in their retracted and extended positions. This limitation makes the device of the '650 patent unsuitable for applications wherein selective control of the toggle wings is essential, examples of such applications include using the fastener as a detent pin, wherein the fastener would hold the workpiece members together without exerting a compressive force between the lock nut and the extended toggle wings, and using the fastener in cases where the user must insert the fastener through the aperture without causing the toggle wings to exert a compressive force against the aperture's wall lining while the actuator pin is not actuated. The device of the '650 patent also does not provide a conduit configuration to allow for communication between the accessible and inaccessible sides of the workpiece members. In addition, the device of the '650 patent requires a relatively large clearance on the inaccessible side of the workpiece members because the extension of the toggle wings is achieved by pivoting the four toggle wings longitudinally outward with respect to four corresponding lock pins installed laterally through the annulus of the sleeve.
Therefore, there exists a need for a retractable fastener device that is capable of extending through an aperture defined in at least one component having a first side and a second side and selectively and retractably engaging the second side so as to selectively prevent the fastener device from being removed from the aperture from the first side. In addition, there further exists a need for a retractable fastener device that is relatively easy to manufacture, simple to install, able to firmly engage a first side and a second side of at least one component, robust, and reusable. There also exists a need for a retractable fastener device that may be easily adjusted to be secured within an aperture defined in at least one component wherein the at least one component may have a varied thickness. There further exists a need for a retractable fastener device having a conduit configured to allow for communication between the first side and the second side of the at least one component when the retractable fastener device is selectively engaged with the second side of the at least one component.